summaryrefslogtreecommitdiff
path: root/test/Sema/constant-conversion.c
blob: bf8221089d8c9707176a57fc13fdb97a1ae4aa4b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
// RUN: %clang_cc1 -fsyntax-only -verify -triple x86_64-apple-darwin %s

// This file tests -Wconstant-conversion, a subcategory of -Wconversion
// which is on by default.

// rdar://problem/6792488
void test_6792488(void) {
  int x = 0x3ff0000000000000U; // expected-warning {{implicit conversion from 'unsigned long' to 'int' changes value from 4607182418800017408 to 0}}
}

void test_7809123(void) {
  struct { int i5 : 5; } a;

  a.i5 = 36; // expected-warning {{implicit truncation from 'int' to bit-field changes value from 36 to 4}}
}

void test() {
  struct { int bit : 1; } a;
  a.bit = 1; // shouldn't warn
}

enum Test2 { K_zero, K_one };
enum Test2 test2(enum Test2 *t) {
  *t = 20;
  return 10; // shouldn't warn
}

void test3() {
  struct A {
    unsigned int foo : 2;
    int bar : 2;
  };

  struct A a = { 0, 10 };            // expected-warning {{implicit truncation from 'int' to bit-field changes value from 10 to -2}}
  struct A b[] = { 0, 10, 0, 0 };    // expected-warning {{implicit truncation from 'int' to bit-field changes value from 10 to -2}}
  struct A c[] = {{10, 0}};          // expected-warning {{implicit truncation from 'int' to bit-field changes value from 10 to 2}}
  struct A d = (struct A) { 10, 0 }; // expected-warning {{implicit truncation from 'int' to bit-field changes value from 10 to 2}}
  struct A e = { .foo = 10 };        // expected-warning {{implicit truncation from 'int' to bit-field changes value from 10 to 2}}
}

void test4() {
  struct A {
    char c : 2;
  } a;

  a.c = 0x101; // expected-warning {{implicit truncation from 'int' to bit-field changes value from 257 to 1}}
}

void test5() {
  struct A {
    _Bool b : 1;
  } a;

  // Don't warn about this implicit conversion to bool, or at least
  // don't warn about it just because it's a bit-field.
  a.b = 100;
}

void test6() {
  // Test that unreachable code doesn't trigger the truncation warning.
  unsigned char x = 0 ? 65535 : 1; // no-warning
  unsigned char y = 1 ? 65535 : 1; // expected-warning {{changes value}}
}

void test7() {
	struct {
		unsigned int twoBits1:2;
		unsigned int twoBits2:2;
		unsigned int reserved:28;
	} f;

	f.twoBits1 = ~0; // no-warning
	f.twoBits1 = ~1; // no-warning
	f.twoBits2 = ~2; // expected-warning {{implicit truncation from 'int' to bit-field changes value from -3 to 1}}
	f.twoBits1 &= ~1; // no-warning
	f.twoBits2 &= ~2; // no-warning
}

void test8() {
  enum E { A, B, C };
  struct { enum E x : 1; } f;
  f.x = C; // expected-warning {{implicit truncation from 'int' to bit-field changes value from 2 to 0}}
}

void test9() {
  const char max_char = 0x7F;
  const short max_short = 0x7FFF;
  const int max_int = 0x7FFFFFFF;

  const short max_char_plus_one = (short)max_char + 1;
  const int max_short_plus_one = (int)max_short + 1;
  const long max_int_plus_one = (long)max_int + 1;

  char new_char = max_char_plus_one;  // expected-warning {{implicit conversion from 'const short' to 'char' changes value from 128 to -128}}
  short new_short = max_short_plus_one;  // expected-warning {{implicit conversion from 'const int' to 'short' changes value from 32768 to -32768}}
  int new_int = max_int_plus_one;  // expected-warning {{implicit conversion from 'const long' to 'int' changes value from 2147483648 to -2147483648}}

  char hex_char = 0x80;
  short hex_short = 0x8000;
  int hex_int = 0x80000000;

  char oct_char = 0200;
  short oct_short = 0100000;
  int oct_int = 020000000000;

  char bin_char = 0b10000000;
  short bin_short = 0b1000000000000000;
  int bin_int = 0b10000000000000000000000000000000;

#define CHAR_MACRO_HEX 0xff
  char macro_char_hex = CHAR_MACRO_HEX;
#define CHAR_MACRO_DEC 255
  char macro_char_dec = CHAR_MACRO_DEC;  // expected-warning {{implicit conversion from 'int' to 'char' changes value from 255 to -1}}

  char array_init[] = { 255, 127, 128, 129, 0 };
}

#define A 1

void test10() {
  struct S {
    unsigned a : 4;
  } s;
  s.a = -1;
  s.a = 15;
  s.a = -8;
  s.a = ~0;
  s.a = ~0U;
  s.a = ~(1<<A);

  s.a = -9;  // expected-warning{{implicit truncation from 'int' to bit-field changes value from -9 to 7}}
  s.a = 16;  // expected-warning{{implicit truncation from 'int' to bit-field changes value from 16 to 0}}
}